Local authorities did not have time to assess the risk posed by a mother's violent partner in the weeks before he murdered her baby, a report has found.
Noah Serra-Morrison, 13 months, died at the hands of Hardeep Hunjan in Luton, in November 2015.
A serious case review said the family was known to children's services in London but its details were not fully considered when they moved to Luton.
Luton Borough Council says it has now changed its procedures.
Baby Noah died as a result of a skull fracture at his home in Crawley Road.
At the time medical experts concluded the child had been slammed against a hard surface. He also had multiple limb fractures consistent with being twisted or swung.
A serious case review (SCR), commissioned by Luton Safeguarding Children Board, described how Noah, referred to as 'Child J', moved to Luton with his mother Ronnie Tayler-Morrison weeks before his death.
The boy's parents had separated and his mother became involved with Hunjan in July 2015.
Hunjan had been bailed to an address in Hull after assaulting a "vulnerable" neighbour in London.
He was able to move in with Tayler-Morrison without children's services' knowledge because the terms of his bail only specified addresses within the M25, the report said.
The review concluded that the safeguarding team in Luton "was experiencing heavy workloads, a disproportionate number of contacts, large turnovers of staff and poor management of resources" at the time of Noah's death.
Workloads were high and "staff did not feel they had sufficient time to read and understand all the information provided by an Ealing social worker," it said.
A spokesman for Luton Council said the review highlighted the inconsistency across all local authorities on the transfer of so-called child in need cases.
"Following the death of Child J, we immediately carried out a review and changed our procedures so that when we are informed by another local authority that they are transferring a child in need case to our area we automatically carry out an independent assessment of the child's needs," he added.
Sheila Lock, independent chair of the Ealing Safeguarding Board, said the authority would be writing to the new children's minister to push for change in the way agencies handle information on families that move between boroughs.
Hunjan, 27, was jailed for life for baby Noah's murder at Luton Crown Court last July. Tayler-Morrison, 22, was jailed for six-and-a-half years for causing or allowing his death.
A spokesman for the NSPCC described the case as "tragic".
"A vulnerable baby boy was subjected to horrific abuse and neglect by the very people who should have been protecting him," he said.